Fair Value Measurements (Schedule Of Fair Value, Assets And Liabilities Measured On Recurring Basis) (Details) - USD ($) $ in Millions | Sep. 30, 2024 | Dec. 31, 2023 |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Risk Management Assets, Net, Current | $ 144 | $ 214 |
Risk Management Assets, Net, Long-term | 6 | 4 |
Risk Management Liabilities, Net, Current | 1 | 0 |
Risk Management | 3 | 2 |
Guarantor Obligations, Current Carrying Value | 0 | 4 |
Accounts Payable and Accrued Liabilities [Member] | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Risk Management Liabilities, Gross Assets | | 0 |
Guarantor Obligations, Current Carrying Value | 0 | 4 |
Accounts Payable and Accrued Liabilities [Member] | Carrying Amount [Member] | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Guarantor Obligations, Current Carrying Value | | 4 |
Accounts Payable and Accrued Liabilities [Member] | Level 1 [Member] | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Guarantor Obligations, Current Carrying Value | | 0 |
Accounts Payable and Accrued Liabilities [Member] | Level 2 [Member] | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Guarantor Obligations, Current Carrying Value | | 4 |
Accounts Payable and Accrued Liabilities [Member] | Level 3 [Member] | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Guarantor Obligations, Current Carrying Value | | 0 |
Commodity Derivatives [Member] | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Risk Management Assets, Net, Current | $ 142 | $ 203 |
Derivative Asset, Current, Statement of Financial Position [Extensible Enumeration] | Risk Management Assets, Net, Current | Risk Management Assets, Net, Current |
Risk Management Assets, Net, Long-term | $ 6 | $ 4 |
Derivative Asset, Noncurrent, Statement of Financial Position [Extensible Enumeration] | Risk Management Assets, Net, Long-term | Risk Management Assets, Net, Long-term |
Risk Management Liabilities, Net, Current | $ 1 | $ 0 |
Derivative Liability, Current, Statement of Financial Position [Extensible Enumeration] | Risk Management Liabilities, Net, Current | Risk Management Liabilities, Net, Current |
Risk Management | $ 3 | $ 2 |
Derivative Liability, Noncurrent, Statement of Financial Position [Extensible Enumeration] | Risk Management | Risk Management |
Commodity Derivatives [Member] | Other Current Assets [Member] | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Risk Management Assets, Gross assets | $ 142 | $ 204 |
Risk Management Assets, Gross Liabilities | 0 | (1) |
Commodity Derivatives [Member] | Other Current Assets [Member] | Level 1 [Member] | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Risk Management Assets, Gross assets | 0 | 0 |
Commodity Derivatives [Member] | Other Current Assets [Member] | Level 2 [Member] | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Risk Management Assets, Gross assets | 142 | 188 |
Commodity Derivatives [Member] | Other Current Assets [Member] | Level 3 [Member] | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Risk Management Assets, Gross assets | 0 | 16 |
Commodity Derivatives [Member] | Other Noncurrent Assets [Member] | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Risk Management Assets, Gross assets | 9 | 5 |
Risk Management Assets, Gross Liabilities | (3) | (1) |
Commodity Derivatives [Member] | Other Noncurrent Assets [Member] | Level 1 [Member] | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Risk Management Assets, Gross assets | 0 | 0 |
Commodity Derivatives [Member] | Other Noncurrent Assets [Member] | Level 2 [Member] | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Risk Management Assets, Gross assets | 9 | 5 |
Commodity Derivatives [Member] | Other Noncurrent Assets [Member] | Level 3 [Member] | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Risk Management Assets, Gross assets | 0 | 0 |
Commodity Derivatives [Member] | Other Current Liabilities [Member] | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Risk Management Liabilities, Gross liabilities | 1 | 1 |
Risk Management Liabilities, Gross Assets | 0 | (1) |
Commodity Derivatives [Member] | Other Current Liabilities [Member] | Level 1 [Member] | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Risk Management Liabilities, Gross liabilities | 1 | 0 |
Commodity Derivatives [Member] | Other Current Liabilities [Member] | Level 2 [Member] | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Risk Management Liabilities, Gross liabilities | 0 | 1 |
Commodity Derivatives [Member] | Other Current Liabilities [Member] | Level 3 [Member] | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Risk Management Liabilities, Gross liabilities | 0 | 0 |
Commodity Derivatives [Member] | Long-term Liabilities [Member] | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Risk Management Liabilities, Gross liabilities | 6 | 3 |
Risk Management Liabilities, Gross Assets | (3) | (1) |
Commodity Derivatives [Member] | Long-term Liabilities [Member] | Level 1 [Member] | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Risk Management Liabilities, Gross liabilities | 0 | 0 |
Commodity Derivatives [Member] | Long-term Liabilities [Member] | Level 2 [Member] | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Risk Management Liabilities, Gross liabilities | 6 | 3 |
Commodity Derivatives [Member] | Long-term Liabilities [Member] | Level 3 [Member] | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Risk Management Liabilities, Gross liabilities | 0 | 0 |
Foreign Currency Derivatives [Member] | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Risk Management Assets, Net, Current | $ 2 | $ 11 |
Derivative Asset, Current, Statement of Financial Position [Extensible Enumeration] | Risk Management Assets, Net, Current | Risk Management Assets, Net, Current |
Foreign Currency Derivatives [Member] | Other Current Assets [Member] | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Risk Management Assets, Gross assets | $ 2 | $ 11 |
Risk Management Assets, Gross Liabilities | 0 | 0 |
Foreign Currency Derivatives [Member] | Other Current Assets [Member] | Level 1 [Member] | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Risk Management Assets, Gross assets | 0 | 0 |
Foreign Currency Derivatives [Member] | Other Current Assets [Member] | Level 2 [Member] | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Risk Management Assets, Gross assets | 2 | 11 |
Foreign Currency Derivatives [Member] | Other Current Assets [Member] | Level 3 [Member] | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Risk Management Assets, Gross assets | $ 0 | $ 0 |